The tube assembly or fitting carrying a refrigerant in an air conditioning system must be securely fastened to the condenser or heat exchanger for proper operation. It is desirable that any fastener should reduce tube assembly costs and allow for a flexible installation.
Typically, the tube assembly which carries the refrigerant to and from the condenser is manufactured and supplied in the specific length and shape necessary for the installation. Because each air conditioning system has a unique tube assembly design requirement, air conditioning suppliers in the aftermarket are forced to maintain extensive inventories of specifically designed tube assemblies at significant cost and risk of obsolescence.
Upon installation, the tube assembly is usually secured to the condenser by a nut type fastener or through the use of a pad or block which is secured by means of a bolt. The problem with using a nut type fastener or a bolted block is controlling the tightening of the nut and the positioning of the tube during installation. If the nut or bolt is over-torqued, there is a risk that the condenser may be damaged through distortion. If the nut or bolt is under-torqued, there is a risk of refrigerant loss with the associated environmental concerns or of incorrectly positioning the tube leading to a possible fracture of the tube.
The present invention includes a fastener for securing a tube assembly to a mating assembly, such as a condenser, that overcomes the foregoing disadvantages. The fastener allows for a reduction in inventory, is easy to install, and provides an environmentally adequate seal between the tube assembly and the condenser.
Inventory and the associated risk of obsolescence is reduced because the fastener and the tube assembly are designed to be used with any air conditioning system. The air conditioning supplied must only stock a set of fasteners and a set of tubes of varying lengths for the tube assembly. The tubes are manufactured straight, but can be bent to any shape required by the installation.
Installation is made easier because the tubes are bent without requiring the installer to assemble a nut or other fastener to the end of the tube. Because the tubes can be easily bent, a very tight bend radius in the tube can be achieved which is critical in many installations because of the tight confines of the engine well. This is also made easier because there is no nut to integrate with the tight bend radius. The tube assembly once properly inserted in the condenser is easily positioned according to one of the tube positioning numbers marked on the fastener. Each tube positioning number corresponds to a particular installation and insures the proper directional alignment of the tube. Once the tube assembly is properly positioned, the fastener is assembled over the end of the tube assembly and securely bolted to the condenser The inner side of the fastener has three projections which lock the tube in position once the bolt is tightened.
Another advantage of the present invention is that the fastener creates an environmentally adequate seal between the tube assembly and the condenser. Before the tube assembly is inserted into the condenser, an "O-Ring" seal is placed over the end of the tube assembly to provide a seal between the tube assembly and the condenser. When the fastener is securely bolted to the condenser, the "O-Ring" seal is compressed creating the environmentally adequate seal.